COMP: Avoid ... operator

To address:

D:\a\ITKPerformanceBenchmarking\ITKPerformanceBenchmarking\src\jsonxx.cc(222): error C2143: syntax error: missing ':' before '...'
D:\a\ITKPerformanceBenchmarking\ITKPerformanceBenchmarking\src\jsonxx.cc(222): error C2059: syntax error: '...'

Author: thewtex

src/jsonxx.cc

@@ -239,6 +239,53 @@ parse_number(std::istream & input, Number & value)
   {
     input.clear();
     input.seekg(rollback);
+
+    switch (input.peek()) {
+        case '-':
+            input.get();
+            value = -std::numeric_limits<Number>::infinity();
+            break;
+        case '+':
+        case '0':
+        case '1':
+        case '2':
+        case '3':
+        case '4':
+        case '5':
+        case '6':
+        case '7':
+        case '8':
+        case '9':
+            input.get();
+            value = std::numeric_limits<Number>::infinity();
+            break;
+        default:
+            return false;
+    }
+
+    int ch;
+    do {
+        ch = input.get();
+    } while (isdigit(ch));
+
+    if (ch != 'E' && ch != 'e') {
+        return false;
+    }
+
+    int exponent;
+    input >> exponent;
+    return !input.fail();
+}
+
+bool parse_bool(std::istream& input, Boolean& value) {
+    if (match("true", input))  {
+        value = true;
+        return true;
+    }
+    if (match("false", input)) {
+        value = false;
+        return true;
+    }
     return false;
   }
   return true;